Clattering

Hello, all. I'm new to the club and not quite sure how this works. But here goes:

I've got a 2000 M Coupe which looks great and runs well...with one unsettling and annoying signature: all four wheels clatter loudly. The noise stops as soon as I touch the brakes, which work fine. Another M Coupe owner tried to identify the source and the nature of the problem, but could not.

If anyone has had a similar experience, identified the problem and solved it, I'd very much like to hear from them. Thanks. Safe driving.

I'd guess if it stops when you hit the brakes, then your brake pads may be the source of your clatter. You can use an inspection mirror and a flashlight to get a look at them with the wheels on the car - look for whether the pads are vertical and how much space there is between the pads and rotors, or if there's any space between the piston and the pad backing plate. It may be easier to see if you pull your wheels off. It would seem a little odd if all 4 caliper pistons were retracting a bit too much after being applied. How recently have the pads been replaced? Plenty of pad thickness? Do you get the noise with new pads?

Thanks for those insights, folks. I've no idea if clips are installed (I bought the M from a used car dealer and didn't know to check.) Are the clips visible with the wheels on, or do I need to jack it up and pull the them? Also, any idea why clips would fail?

You should be able to see them through the wheel.
I've had a clip fall off because I didn't secure it properly.
You can run brake pads without the clips but they are called anti-rattle clips for a reason.